Method of forming surgical cast, and splint therefor



F. WHYTE June 25, 1968 METHOD OF FORMING SURGICAL CAST, AND SPLINT THEREFOR Filed June 21, 1965 2 Sheets-Sheet 1,

,m MY TH NW E v 5 mm. N A R F F. WHYTE June 25, 1968 METHOD OF FORMING SURGICAL CAST, AND SPLINT THEREFOR Filed June 21, 1965 2 Sheets-Sheet FIG. 4

H a 1: m :5 b 11 INVENTOR. FRANCIS WHYTE BY 7 W United States Patent Oftice 3,389,700 Patented June 25, 1968 3,389,700 METHOD OF FORMING SURGICAL CAST, AND SPLINT THEREFOR Francis Whyte, Bedford, Nova Scotia, Canada Filed June 21, 1965, Ser. No. 465,677 9 Claims. (Cl. 12891) ABSTRACT OF THE DISCLOSURE A method and device for forming a surgical cast, and a cast itself, in which the set bandage material forms a circumferential-1y discontinuous wall rendered continuous by a longitudinal connecting splint having tongues symmetrically disposed about a central rib, the bandage material being looped over the tongues. The splint is severable to remove the cast.

The present invention relates to a splint for use in a surgical cast of the type using ribbon bandage material impregnated with a 'hardena'ble substance such as plaster of Paris.

The most common type of surgical cast used to immobilize a limb or other body portion, for instance in set ting a bone fracture, is a plaster cast. This type of castis formed by taking a plaster of Paris bandage (defined as a cotton bandage impregnated with plaster of Paris), immersing the bandage in water, wrapping the bandage in multiple layers about the limb to be immobilized, and allowing the plaster to set whereupon a rigid laminated structure is obtained.

While this type of cast has proved to be economical and effective, its use is attended by the difiicult problem of subsequent removal after its purpose has been served. In order to detach the cast from the limb it is necessary to cut through the east along its entire length and then laterally separate the abutting edges formed by the cut. Because of the thickness and solidity of the cast, the cutting operation requires use of a special type of electric saw or other cast cutter which must be kept on hand for the purpose.

Numerous innovations in the structure of this type of cast have been developed to overcome the problem of its removal while maintaining the rigidity of the structure when in use. In one type of cast a zipper or a separable hinge unit is incorporated longitudinally in the wall of the structure but this development is complicated and expensive since it requires a special construction for the body of the cast itself. In another type of structure a strip cutting device is embedded in the wall of the cast adjacent its inner surface and, when pulled outwardly, will sever the cast longitudinally. In still another variation of plaster cast structure a longitudinal backing strip is embedded in the cast adjacent its inner surface to provide a guard plate or a guide channel adapted to co-operate with a conventional cast cutting instrument. These latter devices facilitate cutting through the cast but do not eliminate the cutting problem itself.

It is an object of the present invention to provide a method of forming a surgical cast which is easily removable after use.

It is a further object of this invention to provide a splint, for use with a surgical cast, which is simple and inexpensive to produce and enables easy removal of the cast by surgical equipment ordinarily at hand.

Still another object of the present invention is to provide a surgical cast, using impregnated ribbon bandage material, which has a circumferentially discontinuous rigid wall of bandage material the edges of which are connected by a splint which is easily severable.

In its broadest aspect the invention resides in a method of forming a surgical cast on a body portion to be immobilized, comprising the steps of: placing on the surface of the body portion a splint of form retaining severable sheet material having a longitudinal central rib and a plurality of tongues symmetrically disposed on each side of, and parallel to, the rib; interlacing with the splint a ribbon bandage impregnated with hardenable material, the interlacing being effected by looping the bandage about one of the tongues, passing the bandage about the body portion, looping the bandage about a second tongue symmetrically disposed with respect to the first tongue, and advancing the bandage in like manner along the splint; and setting the resultant cast structure.

In another aspect the invention resides in a splint for use with impregnated ribbon bandage material to form a surgical cast. The splint comprises an elongated strip of form retaining severable sheet material. The strip has a longitudinal central rib together with a plurality of tongues extending from a transverse support and symmetrically disposed on each side of the central rib and parallel to it. Each tongue is adapted to support a ribbon of impregnated bandage material looped transversely over it whereby the bandage may be interlaced with the strip to form a cast having a circumferentially discontinuous rigid wall of band-age material the juxtaposed edges of which are connected by the splint.

The invention also contemplates a cast formed by the above mentioned splint using the above mentioned method of construction.

An example embodiment of the invention will now be described with reference to the accompanying drawings in which:

FIGURE l is a view in prespective of a splint according to the invention, applied to a limb and showing the initial step of interlacing an impregnated bandage to form a cast;

FIGURE 2 is a view in cross-section taken along the line 22 of FIGURE 1;

FIGURE 3 is a view in cross-section similar to FIG- URE 2 but showing the bandage windings completed about one pair of symmetrically disposed tongues;

FIGURE 4 is a plan view of the structure shown in FIGURE 3;

FIGURE 5 is a view in cross-section similar to FIG- URES 2 and 3 but showing the completed bandage windings along one section of the splint;

FIGURE 6 is a plan view of the cast structure shown in FIGURE 5; and

FIGURE 7 (shown on the sheet containing FIGURES 1 to 3) in a view in perspective showing application of the single outer covering layer of the completed cast.

The embodiment of the invention shown in FIGURE 1 of the drawings consists of a splint comprising an elongated rectangular strip 10 of sheet material, preferably polyethylene. Strip 10 is molded or cut to provide 10ngitudinal 'slots 11 which are arranged in tandem along the length of the strip and in parallel rows across the width of the strip. Each slot 11 is of a width sufficient to receive a ribbon of bandage material inserted laterally into it. In the illustrated embodiment slots 11 'are cut inwardly from each end 12a and 12b of strip 10 approximately one-fifth the length of the strip. Leaving a short uncut portion to act as a transverse support 13, the cutting of slots 11 is continued approximately two-fifths the length of strip 10 spanning its central transverse axis. Slots 11 are spaced inwardly from each side edge 14 of strip 10 in two parallel rows, leaving a central rib 15 extending the length of the strip. At its central transverse axis a portion of strip 10 on each side of rib 15 is removed to form gaps 16. The resultant structure as shown in FIGURE 1 is a splint having a central rib 15 3 with transverse rows of tongues 17 symmetrically disposed about the rib and parallel to it, the tongues being in the form of cantilevers integral with transverse supports 13. It will be seen that groups of tongues 17 a e longitiudinally aligned to extend the length of strip while each tongue is readily accessible at its free end for bending outwardly normal to the plane of strip 10.

To form a cast 18 (see FIGURE 7), strip 10 is applied to the portion of that limb or portion of the body to be immobilized. In FIGURE 1 the splint is shown placed on the anterior surface of a forearm 19 with one end 12a of strip 10 adjacent the pit 20 of the elbow 21 and the other end 12b of the strip extending over the wrist 22 onto the palm 23 of the hand 24 and reaching the base of fingers 24a.

A roll 25 of plaster of Paris bandage 26, comprising a ribbon of cotton bandage impregnated with plaster of Paris, is dipped in tepid water and held until the ensuing bubbling ceases. The bandage is then removed from the water and the excess water is squeezed from it. I

Bandage 26 is wound on forearm 19 by placing end 27 of the bandage on forearm 19 adjacent an outer tongue 17a of strip 10 nearest end 12a of the strip lying adjacent elbow 21 at the proximal end of forearm 19. Bandage 26 is then passed across the posterior surface of forearm 19, say in a clockwise direction, to meet the outer tongue 17b of strip 10 symmetrically disposed with respect to tongue 17a about rib 15. Bandage 26 is then passed under tongue 17b and up through adjoining slot 11b by passing the ribbon of bandage laterally into the slot from end 12a of strip 10. Before passing bandage 26 into slot 11b it is crossed, that is twisted 180 degrees, to reduce its width, the cross portion lying beneath tongue 17b and the width of bandage in the slot being approximately one-third the length of tongue 17b. After bandage 26 has been looped transversely about tongue 17b it is pushed along slot 11b to bear against transverse support 13. This first winding stage is shown in FIGURES 1 and 2. of the drawings.

To continue forming the cast 18, bandage 26 is again passed across the posterior surface of the forearm, this time in a counter-clockwise direction, and similarly engaged with tongue 17a, passing in crossed fashion beneath tongue 17a and up through adjoining slot 11a adjacent support 13.

The above mentioned procedure is repeated three times until bandage 26 is looped on three occasions through each tongue 17 and seven layers of bandage 26 are formed about forearm 19. This stage of the formation of the cast is shown in FIGURES 3 and 4 of the drawings.

The next stage in the formation of cast 18 is to repeat the procedure outlined above but having bandage 26 engage inner tongues 17c, 17d positioned between central rib 15 and outer tongues 17a, 17b respectively. Cast 18 formed to this stage is shown in FIGURES 5 and 6 of the drawings with thirteen layers of bandage 26 circumscribing forearm 19.

Bandage 26 is now advanced diagonally across the posterior surface of the forearm to the next transverse row of parallel tongues 17 and the same steps are repeated, the bandage being first interlaced by three loops with each symmetrical outer tongue 17e, 17f and subsequently interlaced by three loops with each symmetrical inner tongue 17g, 17h. Inlooping about this second row of tongues 17, bandage 26 is passed into slots 11 through gaps 16 on either side of central rib 15.

When the four rows of tongues 17 have been interlaced in the above manner, complete cast 18 has been formed with thirteen layers of plaster of Paris bandage. As best seen in FIGURE 5, cast 18 is circumferentially discontinuous with its longitudinally discontinuous edges 28 spaced apart by central rib 15 of strip 10 and interconnected by the strip. To finish cast 18 it is preferable to form one additional wrapping layer 29 of bandage 26 4 by winding the bandage completely around the entire cast as shown in FIGURE 7.

After completion, cast 18 is polished with water in the conventional manner and then allowed to set.

The nature of polyethylene enables it to be easily cut with an ordinary instrument such as a pair of nurses dressing scissors. Thus when the time comes to remove the cast it may be cut by these scissors along central rib 15, both the central rib of strip 10 and the single wrapping layer 29 of bandage 26 being severed longitudinally along the cast as indicated by broken line 30 in FIGURE 7. After the cut has been completed cast 18 is pulled open by spreading it laterally at out 30.

It will be appreciated that the type of material used for strip 10 may be varied but polyethylene is preferred. Similarly the dimensions of strip 10 and the number of tongues 17 may be varied according to circumstances. For an adult forearm splint an 11 /2" strip 1%" wide and thick will retain its form adequately for the purpose when slotted to form four transverse rows having four tongues 17 in each row. A 3" width bandage is most advantageously employed with a splint of these dimensions. Such bandages are usually provided in fifteen foot rolls and if one roll is not adequate for the purpose then a further roll may be brought into use, the end of the first roll and the beginning of the second roll being overlapped.

Preferably the thickness of strip 10 and the lateral width of tongues 17 should be such that flexibility of the tongues is achieved in 'a direction normal to the plane of the strip but is inhibited in the plane of the strip. In other words, tongues 17 should be bendable upwardly to allow bandage 26 to pass beneath them but should be otherwise relatively rigid. This condition can best be achieved by forming slots 11 so that the width of each tongue 17 is a multiple of the thickness of strip 10.

I claim:

1. A splint, for use with a plaster of Paris bandage to form a surgical cast, comprising a strip of form-retaining severable sheet material having a central longitudinal rib, at least one support transverse to said central rib and being located intermediate the ends thereof, and a plurality of cantilevers extending laterally from each side of said support to provide at least two pairs of tongues symmetrically disposed about each side of said central rib parallel thereto, said tongues being spaced one from another and from said central rib to form slots, each tongue being adapted to support a ribbon of a plaster of Paris bandage material looped transversely thereover whereby said bandage may be interlaced with said splint to form a cast having a circumferentially discontinuous rigid wall of bandage material the juxtaposed edges of which are connected by said splint.

2. A splint as defined in claim 1, in which the sheet material is a thermoplastic material, said tongues being resiliently bendable in a direction normal to the plane of said strip.

3. A splint as defined in claim 2 in which the plastic material is polyethylene.

4. A splint, for use with plaster of Paris bandage to form a plaster cast, comprising an elongated strip of form retaining severable sheet material, said strip being slotted longitudinally to provide a longitudinal central rib, a pair of supports transverse to the rib intermediate its ends, and a pair of tongues extending laterally from each side of each said support on each side of said central rib and parallel thereto, all said tongues being of substantially equal length, the tongues extending from one of said supports being spaced from the adjacent tongues extending from the other of said supports, each tongue being adapted to support said bandage looped transversely thereover whereby the bandage may be interlaced with said splint to form a cast having a 'circumferentially discontinuous rigid wall of bandage material the juxtaposed edges of which are connected by said splint.

5. A splint as defined in claim 4 in which the sheet material is a thermoplastic material, said tongues being resiliently bend-able in a direction normal to the plane of said strip.

6. A splint as defined in claim 5 in which the plastic material is polyethylene.

7. A method of forming a surgical cast on a body portion to be immobilized, comprising the steps of: placing on the surface of said body portion a splint of form retaining severable sheet material having a longitudinal central rib and a plurality of tongues symmetrically disposed on each side of said rib parallel thereto; immersing in water and then interlacing with said splint a ribbon bandage impregnated with plaster of Paris, said interlacing being eifected by looping said bandage about one of said tongues, passing said bandage about said body portion, looping said bandage about a second tongue symmetrically disposed with respect to said first tongue, and advancing the bandage in like manner along said splint; and setting the resultant cast structure by exposure to air.

8. A surgical cast for immobilizing a body portion, comprising a splint of form retaining severable sheet material slotted longitudinally to provide a longitudinal central rib and a plurality of tongues symmetrically disposed on each side of the rib parallel thereto, and a plaster of Paris bandage, said bandage being looped in sequence about each of said tongues and the symmetrically disposed counterpart thereof in advancing order along said splint to form a circumferentially discontinuous wall of bandage material the juxtaposed edges of which are connected by said splint, said bandage being set.

9. A cast as defined in claim 8 including a single layer of circumferentially over-wrapped impregnated bandage material.

References Cited UNITED STATES PATENTS 1,018,452 2/1912 Slaughter 12889 1,212,731 1/1917 Banks 128169 2,318,864 5/1943 Jackson 128-87 2,700,383 1/1955 Moodie 128-87 3,062,370 11/1962 Morin 128-91 3,074,399 1/1963 'Bitting 12887 FOREIGN PATENTS 17,828 8/1896 Great Britain. 1,202,733 1/ 1960 France.

RICHARD A. GAUDET, Primary Examiner.

J. W. HINEY, R. L. FRINKS, Assistant Examiners. 

